adding to growing opposition from medical experts to the Food and Drug Administration’s approval of this controversial drug.
The Institute for Clinical and Economic Review asked one of its expert panels, the California Technology Assessment Forum, to consider the available data about aducanumab and requested that members vote on whether there was sufficient evidence of a net benefit of aducanumab plus supportive care versus supportive care alone. All 15 panelists voted no.
Several panelists, including ICER President Steven D. Pearson, MD, talked about their personal experience with family members who have the disease.
There was universal agreement among the panelists that there is an urgent need for effective medications to treat the disease. However, the panel of clinicians and researchers also agreed that the evidence to date does not show that the drug helps patients with this debilitating disease.
Panelist Sei Lee, MD, a geriatrician at the University of California, San Francisco, said he lost his mother to AD 6 years ago. In addition to his clinical work, Dr. Lee has conducted research focused on improving the targeting of preventive AD interventions for older adults to maximize benefits and minimize harms.
Dr. Lee said he frequently felt completely overwhelmed by the challenges of his mother’s disease.
“I absolutely hear everyone who is saying we need an effective therapy for this,” Dr. Lee said.
Dr. Lee added that, as an experienced researcher who has weighed the aducanumab data, he saw no clear proof of a benefit that would outweigh the drug’s documented side effects in the two phase 3 trials of the drug. Those side effects include temporary brain swelling. Dr. Lee suggested that Biogen do more to address concerns about this side effect, saying it should not be ignored.
“There’s clearly substantial uncertainty” about aducanumab, Dr. Lee said. “If I had to guess, I think the data is stronger for net harm than it is for that benefit.”
Questions persist about the data Biogen used in support of aducanumab after announcing that the drug had failed in a dual-track phase 3 program.
In March 2019, it was announced that two phase 3 clinical trials, EMERGE and ENGAGE, were scrapped because of disappointing results. The trials were intended to show that aducanumab could slow progression of cognitive and functional impairment, as measured by changes in scores on the Clinical Dementia Rating–Sum of Boxes (CDR-SB).
However, in October 2019, there was an about-face – Biogen announced that, in one of the studies, there were positive findings for a subset of patients who received a higher dose of aducanumab.
No treatment benefit was observed in either the high- or low-dose arms at week 78 in the ENGAGE trial. In the EMERGE trial, however, there was a statistically significant difference in change from baseline in CDR-SB score in the high-dose arm (difference vs. placebo, –0.39; 95% confidence interval, –0.69 to –0.09) but not in the low-dose arm, ICER noted in a draft report.
Still, there are questions about whether this difference would translate into clinical benefit. “Although statistically significant, the change in CDR-SB score in the high-dose group was less than the 1- to 2-point change that has been suggested as a minimal clinically important difference,” ICER staff wrote.